Yarn traversing mechanism



Oct. 17, 1967 E. M. STERNBERG YARN TRAVERSING MECHANISM Original FiledFeb. 26. 1965 'l 0-- 1 16.2. a: t r 20 INVENTOR ERNEST M.STERNB RG W t J1.

' ATTORNEY' United States Patent Claims. (Cl. 242-26.1)

The present application constitutes a divisional of application Ser. No.435,636, filed Feb. 26, 1965.

This invention relates to package winding mechanisms for windingstrands, yarns, threads, slivers, or the like, of filamentous materialson cones, tubes, bobbins, or other similar revoluble package supportingmembers at high speeds. More particularly, the invention relates to anovel traversing mechanism for use in winding continuous filamentousmaterial on a spool, bobbin or like holder in a uniform, controllablemanner.

Throughout the instant specification and claims, the term strand isintended to include thread, yarn, sliver, fiber, filament, wire, ribbon,fibrous or filamentary bundles, and the like.

In the textile industry, strands obtained by various processes are woundinto packages on bobbins or like revoluble supporting members. In suchwinding operations, it is necessary to employ some means of axiallytraversing the strand back and forth along the package. Various andsundry traversing means have heretofore been proposed for use in suchwinding operations. These prior devices have ordinarily comprised areciprocating member or guide which travels back and forth adjacent thesurface of the rotating package support member on which the strandmaterial is being wound. In general, the reciprocating motion of theguide member has been accomplished by means of a cam, or the like. As iswidely recognized, such prior cam arrangements suffer from undue wear,are limited and cumbersome in the manner of their manipulation, and lackthe degree of compactness desired in many limited scale operations,particularly those encountered in testing and experimentation.

With these desires and prior art shortcomings in mind, it thereforebecomes a general object of my invention to provide an improvedtraversing mechanism for use in strand winding and packaging operations,which mechanism possesses a compactness of arrangement, flexibility inmanipulation and precision of result heretofore unattained.

A further object is such a traversing mechanism which may beeconomically manufactured in the form of one or more packaging stations.

According to the present invention, the foregoing and other objects areattained by providing an improved traverse mechanism of newfoundcompactness in'arrangement and flexibility of operation, a mechanismwhich effects a uniquely advantageous use of the basic principle ofconverting two independent inputs into a combined differential output tothereby control the program of movement of a traverse guide along astrand package to obtain wide variation in package configuration with ahigh order of control. Basically, such a mechanism takes the form of apair of input elements driven through reciprocal paths of pre-selectedlengths at a pre-determined difference in velocities, which inputelements are linked to drive a reciprocably mounted output element andan associated traversing guide in a direction and at a velocityaccording to the algebraic sum of the individual velocities of the inputelements. A further important aspect of this invention essential tooptimumpackage configurations resides in the provision for a high ratioof input speeds productive of greater uniformity in traverse guide speedand in the provision that such input speeds are relatively prime to oneanother, a feature which minimizes the number ofcoincident reversalpoints experienced in the travel of the traverse guide. As employed inthe instant specification and appended claims, the term relatively primeinput speeds connotes that relationship wherein one of the input speedsis not divisible by the other. (An example of such relationship'beingthe numbers, or speeds, 12 and 25. That is, the input speeds are sorelated as to have no common divisor save unity.)

With regard to the feature of maintaining a high ratio of input speeds,it has been found impractical to operate the present device at ratios ofless than 3:1 where optimum package configurations are to be obtained.At input speed ratios less than 3:1, it has been found that theresulting package often exhibits objectionable ridge formations becauseof an undue lack of uniformity of traverse guide speed. This resultbecomes readily apparent when one considers the program described by atraverse guide driven according to the present invention at an inputspeed ratio of, for example, 2:1. The traverse guide will experience aVariation in velocity between a maximum factor of 2 and a minimum of0.5, a normally intollerable variation; however, at a ratio of inputspeeds of, for example, 11:1, traverse guide velocity will only varybetween the limits of a factor of 6 and 5; similarly, at still higherinput ratios, the percentage variation in guide velocity becomesproportionately smaller. It is therefore preferred to operate theherewith disclosed traverse mechanism at as high a ratio of input speedsas is practicable.

Where it is desired to produce package configurations exhibitingflattened mid-portions, a further important aspect of this inventionresides in the provision of a differential in stroke lengths of theinput elements, an arrangement which causes the traverse guide to traveluniformly over the mid-portion of the package being constructed.Additionally, where it is desired to construct a package exhibiting adifference in tapers adjacent each end, such as is expressed by theefficient tear drop configuration, the helix angle formed in at leastone of the fishing-reeltype winding screws is caused to decrease to aminimum adjacent one lengthwise extremity of the stroke of the inputelement, an arrangement which causes the traverse guide to accelerateits travel over that portion of the package being constructed.

To facilitate a better understanding of the details of construction of apossible embodiment of my invention, reference shall now be had to thedrawings as being illustrative, but not limitative, thereof, whereinlike reference numerals refer to similar parts and in which:

FIG. 1 is a simplified schematic of the invention as characterized by apair of reciprocably mounted, freefioating rack elements driving acombined differential output gear, and

FIG. 2 is a simplified depiction showing one possible alternative drivearrangement using fishing-reel-type reverse helical screws in lieu ofthe pinion arrangement of FIG. 1.

Referring now to the schematic representation of FIG. 2, the traversingmechanism, generally indicated by numeral 10, is seen to comprise a pairof parallel extending, fishing-reel-type reverse helical traversewinding screws 12, ,14, which screws are each characterized by endless,reverse helical cam grooves 16, 18, respectively, formed in the surfacesthereof such that a follower inserted there- .in will trace the groovefrom one end of the screw to the other in a continuous fashion as thescrew is caused .to rotate. Each of the screws 12, 14 has coaxiallymounted .thereon and in sliding engagement therewith a sleeve-like inputelement 20, 22, respectively, each having a follower shoe protrudingfrom its inner surface and sized to snugly engage the endless grooves16, 18. It will be apparent that upon causing the screws to rotate aboutfixed axes, the input elements 20, 22 Will be caused to travel along thelength of the screws at a rate dependent upon both the speed of screwrotation and the helix angle at a given point along the groove (whichangle is that described by a tangent to a given point along the groovewith a line parallel to the axes of rotation of the screws).

An advantageous arrangement for driving the screws at the desired speedratio is found in the provision of a variable speed motor 24 driving atiming belt, chain or the like 27 through power take-off sprocket 26,the belt being entrained about screw sprockets 28, 30 to drive screws12, 14, respectively.

A most beneficial feature of the present invention resides in theprovision of a reciprocating mechanism (which, in the arrangementillustrated in FIG. 2, comprises motor 24, power sprocket 26, timingbelt 27, screw sprockets 28, 30 and winding screws 12, 14) which is sodesigned as to drive the input elements 20, 22 at a high velocity ratiowhich are relatively prime to one another, i.e. indivisible by oneanother. For example, this may be accomplished by providing a 19-toothsprocket as element 28 and a 61-tooth sprocket as element 30, anarrangement resulting in a speed ratio, for a given identity of helixangle, between the input elements of greater than the 3:1 ratioconsidered requisite to satisfactory package formation, as well as beinga speed ratio possessing the relationship of being relatively prime toone another. It is, of course, contemplated that a suitable gear trainmay be incorporated between the motor 24 and the sprockets 28, 30 toproduce still higher ratios of input velocities and a concomitantgreater uniformity in output velocity through the combined differentialoutput gear 62.

The motion of the combined differential output element (the gear 62 inFIG. 2) is transmitted by suitable means, such as a rod 38, to aconventional ringtraveler arrangement normally comprising a ring member40 and a strand traveler 42 mounted to freely slide about the ring witha minimum of friction. Bobbin 44 is driven at high rotative speeds byany suitable means, not shown, to cause the supply strand 46 to travelthrough balloon guide 48, thence through traveler 42 to then beenwrapped about the strand package 50 being formed. By operation of thetraversing mechanism, the ring-traveler assembly is caused to traversebobbin 44 axially at a speed equal or proportional to and in a directionaccording to the algebraic sum of the velocities of the respective inputelements 20, 22. It will be appreciated that, by operation of theinstant traversing mechanism, there is produced a package characterizedby a differential-fill winding wherein the traverse of the yarn travelerguide axially of the package is of uniform, successively displacedstrokes lengthwise of the package during the winding operation.

A further important feature of my invention, as previously mentioned,lies in an arrangement productive of packages exhibiting uniformlyflattened mid-portions. This is readily accomplished by sizing thelongitudinal dimensions of groove 16, 18 to have a pre-chosen differencein effective stroke lengths, this differential being indicated by thedistance labeled D in FIG. 2. By this arrangement it will be appreciatedthat the builder motion described by the ring-traveler will experience auniform residence time over the mid-portion of the package equal toonehalf the difference in effective stroke lengths of the input elements20, 22. By varying this difference in stroke lengths, a package havingany desired length of flattened mid-portion may be formed.

As an alternative to the reverse helical winding screws 12, 14 of FIG.2, the racks 58, 60 which interconnect input elements 20, 22 withdifferential output gear 62 may be driven by pinion gears 64, 66,respectively, as shown in FIG. 1. Depending on the particulararrangement de- 4 sired, the racks 58, 60 may be modified by theaddition of outwardly facing toothed-portions to accommodate the pinionarrangement shown in FIG. 1; of course, the pinion gears may be mountedbetween the rack members, thereby avoiding the need of forming adouble-toothed rack.

It may now be appreciated that there has been herewith disclosed a noveland beneficial traversing mechanism of compact construction which ishighly precise and flexible in operation and which embodies theprinciples and attendant advantages of a combined differential outputmotion being transmitted to the traveler guide. Obviously, numerousmodifications and variations of the present invention, both as to itsconstruction and mode of operation, are possible in light of the aboveteachings. It is, therefore, to be understood that, within the scope ofthe appended claims, the invention may be practiced otherwise than asspecifically described herein.

What is claimed is:

1. In a winding mechanism for use in strand winding operations, atraversing mechanism comprising a pair of reciprocably mounted inputelements, means to reciprocate said elements through paths ofpro-selected lengths at pro-determined difference in velocities, areciprocably mounted output gear, a reciprocably mounted strandtraversing guide responsive to movement of said output element, linkagemeans interconnecting said output element with each of said inputelements and operative to move said output gear according to theindividual movements of said pair of input elements, said linkage meanscomprising a pair of reciprocably mounted rack members, each engagingsaid output gear, and being driven by one of said input elements,whereby said traversing guide is caused to move in a direction and at avelocity according to the algebraic sum of the velocities of said inputelements.

2. The mechanism as recited in claim 1 wherein said reciprocating meanscomprises a pair of rotatably mounted fishing-reel-type winding screws,each characterized by an endless, reverse helical groove formed alongits surface, each of said input elements engaging one of said grooves tobe urged therealong upon rotation of the screw to thereby describe saidreciprocating paths.

3. The mechanism as recited in claim 2 wherein the helix angle describedby at least one of said grooves decreases to a minimum adjacent onelengthwise extremity thereof, whereby said traversing guide reaches amaximum velocity substantially at one extremity of its reciprocation.

4. The mechanism as defined in claim 2 wherein said reciprocating meansis further characterized by a drive means operative to drive said screwsat rotative speeds relatively prime to one another to thereby minimizethe number of coincident reversal points in the travel of saidtraversing guide.

5. In a winding mechanism for use in strand winding operations, animproved traversing mechanism comprising a pair of pinion gears mountedin side-by-side relationship, and output gear, a pair of reciprocablymounted rack members, each engaging said output gear and being driven byone of said pinion gears through paths of preselected lengths at apre-determined difference in velocities, a reciprocably mounted strandtraversing guide responsive to movement of said output gear, wherebysaid guide is caused to move in a direction and at a velocity accordingto the algebraic sum of the velocities of said rack members.

6. The mechanism as defined in claim 1 wherein the reciprocal paths ofsaid input elements are of differential lengths, whereby said traversingguide experiences a maximum residence period during the mid-portion ofits travel to thereby generate a package exhibiting a substantially flatmid-portion equal to one-half the difference in path lengths of saidinput elements.

7 The mechanism as defined in claim 3 wherein said reciprocating meansis further characterized by a drive means operative to drive said screwsat rotative speeds relatively prime to one another to thereby minimizethe number of coincident reversal points in the travel of saidtraversing guide.

8. The mechanism as defined in claim 2 wherein the reciprocal paths ofsaid input elements are of differential iengths whereby said traversingguide experiences a maximum residence period during the mid-portion ofits travel to thereby generate a package exhibiting a substantially flatmid-portion equal to one-half the difference in path lengths of saidinput elements.

9. The mechanism as defined in claim 4 wherein the reciprocal paths ofsaid input elements are of differential lengths whereby said traversingguide experiences a maxi mum residence period during the mid-portion ofits travel to thereby generate a package exhibiting a substantially fiatmid-portion equal to one-half the difference in path lengths of saidinput elements.

10. The mechanism as defined in claim 7 wherein the reciprocal paths ofsaid input elements are of differential lengths whereby said traversingguide experiences a maximum residence period during the mid-portion ofits travel to thereby generate a package exhibiting a substantially fiatmid-portion equal to one-half the difference in path lengths of saidinput elements.

References Cited UNITED STATES PATENTS 2,577,131 12/1951 Keight 242*26.42,629,559 2/1953 Ayala 24226.4 3,243,131 3/1966 Greive 24226.3 FOREIGNPATENTS 45,927 5/ 1962 Poland.

STANLEY N. GILREATH, Primary Examiner.

5. IN A WINDING MECHANISM FOR USE IN STRAND WINDING OPERATIONS, ANIMPROVED TRAVERSING MECHANISM COMPRISING A PAIR OF PINION GEARS MOUNTEDIN SIDE-BY-SIDE RELATIONSHIP, AND OUTPUT GEAR, A PAIR OF RECIPROCABLYMOUNTED RACK MEMBERS, EACH ENGAGING SAID OUTPUT GEAR AND BEING DRIVEN BYONE OF SAID PINION GEARS THROUGH PATHS OF PRESELECTED LENGTHS AT APRE-DETERMINED DIFFERENCE IN VELOCITIES, A RECIPROCABLY MOUNTED STRANDTRAVERSING GUIDE RE-